Instrument for inserting an interspinous process implant

ABSTRACT

An insertion device for deploying an implant includes an elongated main body having a distal locking portion for coupling to the implant and a proximal handle portion. The main body defines a central passage and the distal locking portion has outer ridges and slots to allow the outer ridges to flex radially inward when mounting to the implant. A plunger slides in the central passage for movement between an unlocked position for mounting the implant on the distal locking portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the actuation plunger to move the blades from the stowed position to the deployed position. A spike cap drive rotatably mounts on the main body having a socket end for engaging a drive nut on the implant to, in turn, move the spike cap.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to U.S. PatentApplication Ser. No. 61/828,384, filed May 29, 2013, which applicationis incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject technology is directed to instruments for inserting spinalimplants, and more particularly, to an insertion instrument that iseasily assembled and disassembled for required cleaning while being ableto effectively deploy an interspinous process implant for spinalstabilization, for percutaneous placement in a target interspinousprocess space, wherein the implant can also serve as a fusion cagespacer to treat lumbar spinal stenosis.

2. Description of Related Art

The spine consists of a column of twenty-four vertebrae that extend fromthe skull to the hips. Discs of soft tissue are disposed betweenadjacent vertebrae. The vertebrae provide support for the head and body,while the discs act as cushions. In addition, the spine encloses andprotects the spinal cord, defining a bony channel around the spinalcord, called the spinal canal. There is normally a space between thespinal cord and the borders of the spinal canal so that the spinal cordand the nerves associated therewith are not pinched.

Over time, the ligaments and bone that surround the spinal canal canthicken and harden, resulting in a narrowing of the spinal canal andcompression of the spinal cord or nerve roots. This condition is calledspinal stenosis, which results in pain and numbness in the back andlegs, weakness and/or a loss of balance. These symptoms often increaseafter walking or standing for a period of time.

There are a number of non-surgical treatments for spinal stenosis. Theseinclude non-steroidal anti-inflammatory drugs to reduce the swelling andpain, and corticosteroid injections to reduce swelling and treat acutepain. While some patients may experience relief from symptoms of spinalstenosis with such treatments, many do not, and thus turn to surgicaltreatment. Some surgical procedures for treating spinal stenosis aredecompressive laminectomy and interspinous process decompression (IPD).A well-known implant used for performing IPD surgery is the X-STOP®device, which is described in U.S. Pat. No. 6,419,676, the disclosure ofwhich is herein incorporated by reference in its entirety. Anotherinterspinous process implant placed in a minimally invasive surgicalprocedure is disclosed in U.S. Patent Application Publication2008/0243250, which is also incorporated herein by reference in itsentirety.

Still another interspinous process implant placed in a minimallyinvasive surgical procedure is disclosed in U.S. Patent ApplicationPublication 2010/0234889, which is also incorporated herein by referencein its entirety. One aspect of effective insertion of these implants isto provide a low profile instrument for deploying the implant. Often,the insertion instrument has several moving parts. Because of the costof the insertion instruments, the instruments are re-used many times.For such insertion instruments to be re-used, the insertion instrumentsmust be properly and fully cleaned without damage or loss of thecomponents.

SUMMARY OF THE INVENTION

It would be advantageous to provide an insertion instrument fordeploying spinal implants that can be easily disassembled for cleaningand assembled for use.

In one embodiment, the subject technology is directed to an insertiondevice for a spinal implant, wherein the spinal implant includes: a) anelongated body to function as a spacer placed in a target interspinousprocess space between two adjacent spinous processes, wherein the bodydefines an interior and a proximal internal recess for access to theinterior, the proximal internal recess forming a transverse groove; b) adistal anchor that is at least partially threaded and has opposingradially deployable blades mounted for rotation about a pin transverselymounted in the interior; c) a proximal anchor including a spike capmounted to slide along the body and a drive nut mounted for longitudinalmovement along the body between a first position spaced apart from thedistal anchor and a second position relatively closer to the distalanchor to thereby compress the two adjacent spinous processes betweenthe spike cap and the distal anchor; and d) an actuation plungerslidably inside the interior for moving the blades from astowed/insertion position to an implant deployed position.

The insertion device includes an elongated main body having a distallocking portion for coupling to the implant and a proximal handleportion. The main body defines a central passage and the distal lockingportion has outer ridges. The at least one slot allows at least one ofthe outer ridges to flex radially inward. A plunger slides in thecentral passage for movement between an unlocked position for mountingthe implant on the distal locking portion, a locked position within theslot for locking the implant on the distal locking portion, and aninsertion instrument deployed position for deploying the actuationplunger to move the blades from the stowed position to the deployedposition. A spike cap drive rotatably mounts on the main body having asocket end for engaging the drive nut to, in turn, move the spike cap.

Preferably, the insertion instrument includes a plunger stop coupled tothe main body. The plunger stop has a central passage substantiallyaligned with the central passage of the main body, wherein: the plungerstop has a boss protruding into the central passage; and the plungerforms a three-part groove that captures the boss as the plunger slidesand rotates within the central passage, the three-part groove having afirst axial part that defines the unlocked position, an intermediateradial part that defines the locked position, and a second axial partthat defines the insertion instrument deployed position. When theimplant is mounted, in the unlocked position, the outer ridges areengaged in the transverse groove. In the locked position, the outerridges are engaged in the transverse groove and the plunger extendsthrough the central passage to be concentric with the outer ridges. Inthe insertion instrument deployed position, the plunger extends out ofthe central passage to move the actuation plunger of the implant.

As the size of the implant may vary, adapters are matched to the implantfor coupling the socket end to the drive nut of the implant. The spikecap may also be keyed to the implant body to prevent rotation whendriven. The implant has flat portions that allow efficient compressionof the implant when engaged in the spinous processes.

In another embodiment, the subject technology is directed to aninstrument for inserting an implant having a threaded body, selectivelydeployable distal blades, and a selectively deployable proximal anchor.The instrument includes an elongated main body having a proximal handleportion that defines a central passage and a distal portion thatselectively couples to the implant. A plunger slides in the centralpassage to fix the implant to the elongated main body and deploy thedistal blades. A spike cap drive is concentrically located about theplunger to deploy the proximal anchor. Preferably, the implant definesan interior with a transverse groove, the distal portion snaps into thetransverse groove, and the plunger slides down central passage toprevent the distal portion from unsnapping from the transverse groove.The plunger can move between an unlocked position for mounting theimplant on the distal portion, a locked position for locking the implanton the distal locking portion, and an insertion instrument deployedposition for deploying the blade.

In still another embodiment, the subject technology is directed to aninsertion instrument for inserting an implant having a body that definesa mounting recess. The insertion instrument includes an elongated mainbody having a proximal handle portion and a slotted distal portion thatselectively couples to the mounting recess of the implant. A plungerslides in a central passage of the elongated main body for fixing theimplant to the elongated main body by selectively filling the centralpassage within the slotted distal portion. Preferably, the implantdefines an interior connected to the mounting recess. The implant mayfurther include selectively deployable distal blades, and the plungerdeploys the distal blades by extending out of the central passage intothe interior.

The implant can further include a selectively deployable proximal anchorand the insertion instrument further comprises a spike cap driveconcentrically located about the plunger and elongated main body todeploy the proximal anchor. The mounting recess may have a transversegroove so that the distal portion has ridges that snap into thetransverse groove.

It should be appreciated that the present technology can be implementedand utilized in numerous ways, including without limitation as aprocess, an apparatus, a system, a device, a method for applications nowknown and later developed. These and other unique features of thetechnology disclosed herein will become more readily apparent from thefollowing description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

So that those skilled in the art to which the subject invention relateswill readily understand how to make and use the insertion instrument ofthe subject technology without undue experimentation, embodimentsthereof will be described in detail herein below with reference to thefollowing figures.

FIG. 1 is a perspective view of an insertion instrument in accordancewith a first exemplary embodiment of the subject technology.

FIG. 2 is a perspective view of the insertion instrument of FIG. 1 withan implant in accordance with a first exemplary embodiment of thesubject technology.

FIG. 3 is an exploded view of the insertion instrument of FIG. 1,illustrating the components thereof.

FIG. 4 is a further exploded view of the spike cap drive of theinsertion instrument of FIG. 1, illustrating the components thereof.

FIG. 5 is a perspective view of the main body ready to engage the spikecap drive of the insertion instrument of FIG. 1.

FIG. 6 is a further exploded view of the plunger and plunger knob of theinsertion instrument of FIG. 1, illustrating the components thereof.

FIG. 7 is a perspective view of the plunger stop being coupled to themain body of the insertion instrument of FIG. 1.

FIG. 8 is a perspective view of the plunger being coupled to the mainbody of the insertion instrument of FIG. 1.

FIG. 9 is a perspective view of the assembled main body of the insertioninstrument of FIG. 1.

FIG. 10 is a cross-sectional view of the insertion instrument of FIG. 9taken at line 10-10 of FIG. 9, where the plunger is an unlockedposition.

FIG. 11 is a perspective view of the implant with blades in a stowedposition.

FIG. 12 is a perspective view of the implant with blades in a deployedposition.

FIG. 13 is a rear exploded view of the implant in accordance with thesubject technology.

FIG. 14 is a front exploded view of the implant in accordance with thesubject technology.

FIG. 15 is a cross-sectional view of the implant of FIGS. 11-14 taken atline 15-15 of FIG. 11, where the distal anchor elements are in a stowedposition.

FIG. 16 is a cross-sectional view of the implant of FIGS. 11-14 taken atline 16-16 of FIG. 11, where the distal anchor elements are in adeployed position.

FIG. 17 is a perspective view of the spike cap drive being retractedfrom the distal tip of the main body of the insertion instrument of FIG.1.

FIG. 18 is a perspective view of the adapter mounted on the spike capdrive of the instrument of FIG. 1 about to be coupled to the implant.

FIG. 19 is a side elevational view of the insertion instrument of FIG. 1with the implant mounted thereon.

FIG. 20 is a perspective view, illustrating an implant in preparation tobe installed dorsally.

FIG. 21 is a dorsal view of an implant within an introducer tube duringlateral insertion thereof.

FIG. 22 is a dorsal view illustrating the implant being screwed into atarget interspinous process space.

FIG. 23 is a perspective view of the insertion instrument with theplunger stop actuated to move the plunger from the locked to thedeployed position.

FIG. 24 is a cross-sectional view of the insertion instrument showingthe plunger and plunger stop as the implant blades are being deployed.

FIG. 25 is a perspective view of the insertion instrument illustratingthe spike cap drive being utilized to turn the hex nut of the implant.

FIG. 26 is a cross-sectional view of the insertion instrument showingthe plunger and plunger stop in the locked position.

FIG. 27 is cross-sectional view illustrating the deployment of theblades of the implant.

FIG. 28 is a cross-sectional view illustrating the spike cap drivesecuring the implant to the spinous processes.

FIG. 29 is a perspective view of the insertion instrument with theplunger being retracted from the implant in preparation to remove theinsertion instrument from the implant after deployment of the implant inthe spinal column.

FIG. 30 is a dorsal cross-sectional view of the implant fixed in thespinal column with the insertion instrument removed.

DETAILED DESCRIPTION

The present disclosure overcomes many of the prior art problemsassociated with instruments for inserting spinal implants and otherdevices such as cage spacers and the like. The advantages and otherfeatures of the instruments and methods disclosed herein will becomemore readily apparent to those having ordinary skill in the art from thefollowing detailed description of certain preferred embodiments taken inconjunction with the drawings which set forth representative embodimentsof the present invention and wherein like reference numerals identifysimilar structural elements.

All relative descriptions herein such as left, right, up, and down arewith reference to the Figures, and not meant in a limiting sense. Theillustrated embodiments can be understood as providing exemplaryfeatures of varying detail of certain embodiments, and therefore,features, components, modules, elements, and/or aspects of theillustrations can be otherwise combined, interconnected, sequenced,separated, interchanged, positioned, and/or rearranged withoutmaterially departing from the disclosed systems or methods. The shapesand sizes of components are also exemplary and unless otherwisespecified, can be altered without materially affecting or limiting thedisclosed technology.

Insertion Instrument

Referring now to FIG. 1, a perspective view of an assembled instrument100 for inserting an implant in accordance with the subject technologyis shown. The instrument 100 is particularly useful for insertinginterspinous process implants and fusion cage spacers in accordance withthose shown in U.S. PG Pub. No. 2010/0234889 (the '889 application).Referring additionally to FIG. 2, a perspective view of the insertioninstrument 100 mounted with an implant 200 in accordance with the '889application is shown.

After use, the instrument 100 can be disassembled easily to allow forfull and proper cleaning, then reassembled to be used again. Preferably,the components of the instrument 100 are fabricated from medical gradestainless steel, alloys, and/or polymers (e.g., RULON, PEEK) or anotherlike durable material to allow for repeated use, cleaning and reuse.

Referring to FIG. 3, an exploded view of the instrument 100 with animplant 200 is shown. The instrument 100 includes an elongated main body102 having a proximal handle portion 104 that defines a central passage106 and a distal portion 108 that selectively couples to the implant200. The distal portion 108 forms axial slots 109 that allowscompression of the tip 113. The tip 113 is roughly hexagonal shaped butas a result of the opposing slots 109, the tip 113 becomes two opposing,spaced apart “V” in cross-sectional shape. The tip 113 has four outerridges 111, one ridge 111 on each flat section of the V-shape. Thehandle portion 104 also has stripes 127 to provide visual references tothe user.

The handle portion 131 has a distal guide portion 133. The handleportion 104 of the main body 102 also has a first pair of opposinglocking tabs 115. The locking tabs 115 are hingedly connected to themain body 102 to rotate radially inward and outward by the surgeon orsurgical assistant. The handle portion 104 also has a second pair ofopposing locking tabs 117 that are located relatively proximallycompared to the first locking tabs 115. The second locking tabs 117 arealso hingedly connected to the main body 102 to rotate radially inwardand outward by the user. The handle portion 104 defines an axial recess134. The axial recess 134 is formed by an angled surface 135 (best seenin FIG. 7).

The main body 102 also forms an axial wing slot 103 with locationindicia 105 a-c adjacent the wing slot 103 as described in more detailwith reference to FIG. 23 among other figures herein. The indicia 105a-c combine with the reference notch 131 on the wings to indicate“unlocked,” “locked” and “deployed” positions of the instrument 100,respectively, as described in more detail below. The main body 102 andspike cap drive 104 includes alignment indicia 123,127 in the form ofstripes 127 and an arrow 123, respectively.

A plunger 110 slides in the central passage 106. The plunger 110 has adistal pushing end 112 and a proximal locking end 114. The proximallocking end 114 has a relatively thicker radius that includes a seriesof spaced apart radial holes 118. Opposing radial wings 120 are formedadjacent a proximal recess 122. The radial wings 120 include a referencenotch 131. In FIG. 3, the plunger 110 is shown coupled to a plunger knob126.

Referring now to FIG. 6, an exploded view of the plunger 110 and plungerknob 126 is shown. The proximal recess 122 has internal threads that areleft-handed. The proximal locking end 114 also forms a three-part groove116. The three-part groove 116 has a first distal axial groove portion119 and a second proximal axial groove portion 125. Intermediate thegroove portions 119, 125, the proximal locking end 114 forms a radialgroove portion 121.

A plunger knob 126 has an externally threaded proximal end 128 thatthreadably couples to the axial threaded post 124 of the plunger 110.The plunger knob 126 has a proximal handle portion 130 for gripping tomove the plunger 110 in the central passage 106. At the distal end ofthe handle portion 130, the plunger knob 126 has an annular recess 142that extends completely around the plunger knob 126.

Referring again to FIG. 3 as well as FIGS. 7 and 9, a plunger stop 132seats in a recess 134 formed in the handle portion 104 of the main body102 to guide the plunger 110 within the main body 102. The plunger stop132 has two outer opposing lands 138 that facilitate a user holding theplunger stop 132 and manipulating position of the plunger stop 132 withtheir thumbs. The plunger stop 132 has tubular portion 137 that definesan axial passage 136 for receiving the plunger locking end 114. A boss139, best seen in FIGS. 7 and 10, extends radially inward from the axialpassage 136 to engage the groove 116 of the plunger locking end 114. Abiasing spring 141 surrounds the tubular portion 137 such that ends 143of the spring 141 extend outward.

Still referring to FIG. 3, a spike cap drive 140 defines an axialpassage 144 for receiving the distal end 108 of the main body 102. Thespike cap drive 140 has a proximal portion 146 that includes arelatively larger radius handle portion 148 with a smaller radiusinterlocking portion 150. The interlocking portion 150 defines anannular groove 152 for interacting with the main body 102. A tubularintermediate portion 154 extends from the handle portion 148 andslidingly receives a drive shaft 160. The drive shaft 160 terminates ina socket end 156. The socket end 156 is also tubular but forms a squareopening 158 for coupling to the implant 200. The socket end 156 alsoforms a transverse square locking passage 157.

The drive shaft 160 is also able to be locked in a retracted positionwithin the intermediate portion 154. Referring now to FIG. 4, anexploded view of the spike cap drive 140 is shown. The spike cap drive140 has a spring 163 mounted within the intermediate portion 154 forbiasing the drive shaft 160 distally. So, in order to lock the driveshaft 160 in a retracted position, the bias of the spring 163 must beovercome. To accomplish this locking, the drive shaft 160 forms twoopposing complimentary slots 161 (only one slot 161 can be seen) andpins 165 mount in opposing pin holes 167 on the intermediate portion154. When assembled, the pins 165 ride in the respective slots 161 sothat upon fully pushing the drive shaft 160 in the intermediate portion154, a small rotation of the drive shaft 160 will set the pins 165 in aradial portion 164 of the slots 161 and retain the spike cap drive 140in this compressed position.

Referring again to FIG. 3, an adapter 170 attaches to the square opening158 of the spike cap drive 140 to provide a hex socket 172 for couplingto the implant 200. The hex socket 172 can vary in size to accommodatedifferent size implants 200. The adapter 170 has a central axial passage173 to slide over the tip 113 of the main body 102. The adapter 170 hasa standard male square open proximal end 174 to couple to the squareopening 158. The proximal end 174 has two opposing rigid legs 175intermediate two opposing flexible legs 176. Each of the flexible legs176 has a locking tab 177 so that as the proximal end 174 is pushed intothe square opening 158 of the spike cap drive 140, the legs 176 deflectto allow easy insertion, then the tabs 177 couple to the transverselocking passage 157 to securely retain the adapter 170 on the driveshaft 160. To remove the adapter 170, the locking tabs 177 are simplydepressed while retracting the adapter 170. The adapter 170 also hasopposing outer axial alignment ridges 178.

The Implant

The implant 200 may take a variety of different configurations andsizes. Preferably, the implant is useful for treatment ofspondylolisthesis, central and foraminal lumbar stenosis, degenerativedisc disease and the like. Beneficially, the implant 200 ispercutaneously placed, provides stabilization of the spine, can be usedwith bone graft material to promote fusion, requires less than a 2.6 cmincision, and can be inserted with local or general anesthesia. As such,the recovery time is relatively quicker and the hospital stay isrelatively shorter.

FIGS. 11-16 illustrate in detail the interspinous process implant 200for use the with insertion instrument 100. The implant 200 includes abody 212, providing overall structure to the implant 200. The body 212,as illustrated, is provided with threads 222 for facilitating insertionof the implant 200 into a target interspinous process space 382 (FIGS.20-22, 27, 28 and 30), as will be described in more detail below inconnection with FIGS. 20-30, as well as for providing additionalengagement with the anatomy of the patient in the target interspinousprocess space 382. Further, the threads 222 permit rotational engagementbetween the body 212 and a proximal nut 235, provided to securely engagethe implant 200 with interspinous processes 381 a, 381 b adjacent thetarget interspinous process space 382, which will be described in moredetail below. Alternatively, the implant 200 can be provided withoutthreads thereon, or with threads provided only on a portion thereof forone of the foregoing functions. That is, if desired, threads 222 can beprovided only on the proximal end of the body 112, for engaging the nut235 and not on the distal portion, or vice versa.

The implant 200 include a distal anchor portion, which is configured astwo opposed deployable blades 220 (220 a, 220 b). The blades 220 areprovided with a common pivot, defined by a pin 259 passing therethrough,as well as through the body 212. Use of a common pivot advantageouslyminimizes the space required for housing all elements within the body212 in their stowed state, although variations from this preciseconfiguration are possible. For example, two separate pivots can beprovided for each blade 220 a, 220 b, still in keeping with theinvention. The blades 220, as illustrated, are provided with proximallydirected spikes 224 for engaging the relevant adjacent bony anatomy,such as the spinous processes 381 a,381 b. The blades 220 canalternatively be provided without such spikes 224.

The blades 220 a, 220 b are respectively provided with hinge portions223 a, 223 b for engaging the pin 259. In the illustrated embodiment,one hinge portion 223 a is shaped as a clevis, while the other 223 b isshaped to fit within the clevis-shaped hinge portion 223 a.

In the illustrated embodiment, an implant plunger 226 is provided andincludes a head portion 228 shaped and configured to act as a cam andcooperate with inner cam surfaces 240 formed on each of the blades 220a, 220 b, as described above. As the plunger head 228 moves distally,cam surfaces 240 of the blades 220 a, 220 b follow the outer surface ofthe plunger head 228, and urge the blades 220 a, 220 b radiallyoutwardly. In addition, the plunger 226 can include, as described above,a proximal head 225 having a proximal internal recess 221, and an angleddistal surface to facilitate distally-directed urging andproximal-directed urging, respectively, applied from the proximaldirection.

Preferably, the implant plunger 226 also includes a recess 229, forsecurely engaging a resilient catch 227. The catch 227 is configured tointerface between the implant plunger 226 and internal surface featuresof the body 212, such as annular grooves or recesses 254. As described,the resilient catch 227 permits axial movement of the implant plunger226, and in conjunction with the above-described internal surfacefeatures of the body 212, defined positions at which the implant plunger226 is held, inhibiting unintentional movement therefrom. The catch 227can be formed of any suitable material or configuration, such as from aresilient material, such as an elastomer, or as a resilient structure,such as a toroidal metallic coil, or a combination of these, forexample. The catch 227 can be, in accordance with the invention, acanted coil, such as a Bal Latch™, available from Bal Seal Engineering,Inc. of Foothill Ranch, Calif., USA.

When deployed, the blades 220 function in concert with the spike cap230, which is axially moveable along the length of the implant 200. Thenut 235 includes threads on its inner surface that engage the threads222 provided on the outer surface of the body 212. Accordingly,rotational movement of the nut 235 yields axial movement thereof. Whenthat axial movement is in the distal direction, the nut 235 urges thespike cap 230 distally until the spike cap 230 abuts the bony structures(e.g. spinous processes 381 a, 381 b) surrounding the targetinterspinous process space 382. If provided, protrusions or spikes 234on the proximal anchor portion facilitate engagement with the bone andthus stabilization of the entire vertebrae-implant construct.

As illustrated, opposed flat portions 217, comprising upper and lowerflat portions 217 a, 217 b, respectively, guide correspondingly shaped(e.g., flat) portions 237 of the spike cap 230, permitting axialmovement but inhibiting rotational movement thereof, during movement ofthe nut 235. A lock washer 233 or equivalent feature can be provided toinhibit unintentional loosening of the nut 235 following implantationand deployment of the blades 220 a, 220 b.

With reference to the cross-sectional views of FIGS. 15 and 16, in theillustrated embodiment, the blades 220 can be provided with an internalspring element 281, spanning between respective recess in each of theblades 220 a, 220 b. The spring element 281 can be provided straight tomaintain the blades 220 a, 220 b deployed (open) normally, oralternatively, bent, to maintain the blades 220 a, 220 b stowed(contracted) normally. In accordance with one aspect, the spring element281 is provided bent, and urges the blades 220 a, 220 b inwardly, towardthe stowed position, prior to and during implantation. Thus, inconnection with the implant plunger 226, the spring 281 serves tomaintain a position of the blades 220. As illustrated, when the implantplunger 226 is fully extended, a head portion 228 thereof engages acorresponding detent 249 in the blades 220 a, 220 b. The engagement ofthe detent 249 by the head portion 228 further ensures secure deploymentof the blades 220 a, 220 b.

The spring element 281 can alternatively be provided as normallystraight, urging the blades 220 a, 220 b outwardly toward the deployedposition, prior to, during and following implantation. Duringimplantation, however, the spring element 281 permits inward rotation ofthe blades 220 a, 220 b, temporarily bending the spring element 281 inthe process. Thus, during implantation the spring 281 serves to maintaina position of the blades 220 a, 220 b against externally-applied forces.Once placed in the target interspinous process space 382, the implantplunger 226 can be urged distally in order to lock the blades 220 a, 220b in the deployed position. Engagement of the detent 249 by the headportion 228 of the implant plunger 226 further ensures maintenance ofthat position.

The body 212 of the implant 200 includes at its proximal end, anexpanded-diameter portion 213, defining a proximal-most limit fortraveling of the nut 235 and spike cap 230. Also in the proximal endportion, formed within the proximal internal recess 250, is a shapedsocket 251 for engagement with the insertion instrument 100 as discussedin more detail below. As illustrated, the socket 251 is substantiallyhexagonal, with flat portions defined at regular angular intervals.Practicable departures from the precise configuration illustrated arepossible. The shaped socket 251 facilitates mutual rotational engagementbetween the implant 200 and the insertion instrument 100.

Also provided in connection with the socket 251, are transverse grooves253, which, in conjunction with the tip 113 of the main body 102 andpushing end 112 of the plunger 110 mount and lock the implant 100 to theinsertion instrument 100. The mounting and/or locking elements on theinsertion instrument can also be, for example, a resiliently andoptionally lockable protrusion extending laterally (i.e., radially) fromthe insertion instrument. The lockable protrusion may be, for example, alockable spring-loaded spherical element, for example.

The implant 200 can be provided with one or more apertures 214 to permitpacking of the implant, such as in the proximal internal recess 250thereof, with osteogenesis-promoting substances to facilitate boneingrowth and/or fusion, such as demineralized bone.

Assembly of the Insertion Instrument

Referring now to FIGS. 3 and 5, in order to assemble the insertioninstrument 100, the distal portion 108 of the main body 102 is insertedinto the axial passage 144 of the spike cap drive 140 until the proximalhandle portion 104 is flush against the handle portion 148 of the spikecap drive 140. The first locking tabs 115 are rotated from the openposition shown in FIG. 5 to the closed position shown in FIG. 1. Thefirst locking tabs 115 axially lock the main body 102 and the spike capdrive 140 together. The locking occurs by the locking tabs 115 extendinginto the annular groove 152 of the spike cap drive 140 and snappingfixedly into place. Preferably, the user hears an audible click to knowthat the engagement of the tabs 115 into the groove 152 has been fullycompleted. The spike cap drive 140 can still rotate with respect to themain body 102. The distal guide portion 133 of the main body 102 issized so that the spike cap drive 140 rotates smoothly. A suitablematerial or coating may be used in contact areas to prevent wear andgalling.

Referring to FIGS. 6-8, the threaded distal end 128 of the plunger knob126 is partially threaded into the recess 122 of the plunger 110 asshown in FIG. 6. The plunger knob 126 is turned counter-clockwisebecause the threading is left-handed. The plunger stop 132 is seated inthe recess 134 of the main body 102 as shown in FIG. 7. The plunger stop132 is seated with the ends 143 of the spring 141 against the angledsurface 135 so that the plunger stop 132 will be biased for clockwiserotation when one looks down the insertion instrument 100 from theproximal to the distal direction.

While holding the plunger stop 132 in place with one hand, the plunger110 can be partially inserted into the central passage 106 of the mainbody 102 by holding the plunger knob 126 with the other hand as shown inFIG. 8. As noted above, at this point, the plunger knob 126 need not becompletely threaded into the plunger 110 but the plunger knob 126 maybe. The radial wings 120 will slide in the slot 103 of the main body 102so that the reference notch 131 is adjacent the indicia 105 a-c.

As the plunger 110 is inserted through the plunger stop 132, the userapplies rotational force to the plunger stop 132 by using the thumblands 138 to make sure that the plunger stop boss 139 aligns with thedistal axial groove portion 119. The user must apply enough force toovercome the spring 141 because the spring 141 biases the plunger stop132 the axial groove portion 119 towards the radial groove portion 121.Once the plunger stop boss 139 is in the distal axial groove portion119, as shown in FIG. 10, and the plunger knob 126 is flush against theproximal handle portion 104 of the main body 102, the second pair ofopposing locking tabs 117 are clicked into the annular recess 142 of theplunger knob 126 as shown in FIG. 9. As a result, the plunger 110 andplunger knob 126 are axially locked to the main body 102.

Referring to FIG. 10, when the plunger stop boss 139 is in the firstdistal axial groove portion 119, rotation of the plunger 110 isprevented until the boss 139 reaches the radial groove portion 121 ofthe plunger 110. However, rotation of the plunger knob 126 is stillpossible.

While the boss 139 is in the axial groove portion 119 and both pairs oflocking tabs 115, 117 are properly secured, the instrument 100 is in the“unlocked” position as visually indicated to the user by the referencenotch 131 being adjacent the unlocked indicia 105 a. “Unlocked” refersto the implant 200 not being secured to the insertion instrument 100even if the implant 200 is mounted on the tip 113. The implant 200 islocked to the insertion instrument 100 by deploying the plunger 110 asdescribed below.

Locking the Implant to the Insertion Instrument

As would be understood from the description above, even once assembled,several components of the insertion instrument 100 are able to move.Thus, it is important to make sure the moving components are in theproper position to be ready for mounting the implant 200. In particular,the plunger 110 should be fully retracted into the unlocked position byturning the plunger knob 126 counter clockwise while rotating andholding the plunger stop 132 to allow plunger 110 travel (i.e., the boss139 of the plunger stop 132 is aligned with the first axial distalgroove portion 119 of the plunger 110 as shown in FIG. 10). Once theplunger 110 is fully retracted, the reference notch 131 will indicatefully unlocked on the unlocked indicia 105 a.

Turning to the selection of the implant 200, it is envisioned that theimplant 200 comes in a variety of sizes so that an appropriate size canbe selected for a desired amount of interspinous distraction. Anytechnique now known and later developed may be used to determine theproper interspinous distraction. Once the proper size implant 200 isselected, the corresponding or matching adapter 170 can be selected.Once the adapter 170 has been chosen, the implant 200 can be mounted onthe insertion instrument 100.

Referring now to FIG. 17, the distal portion 108 of the main body 102 isuncovered by sliding the drive shaft 160 into the intermediate portion154 of the spike cap drive 140. The drive shaft 160 is initiallyprevented from rotation because the pins 165 are riding in the slots 161(best seen in FIG. 4). However, once the pins 165 bottom out in theslots 161, the user can hold the handle portion 148 and rotate the driveshaft 160 so the pins 165 come to rest in the radial portion 164 of theslots 161. As a result, the drive shaft 160 is retained in theintermediate portion 154 and will stay retracted even when released bythe user.

Referring now to FIG. 18, the matching adapter 170 is slid over thedistal portion 108 of the main body 102 so that the legs 175, 176 can beinserted into the square opening 158. Preferably, the locking tabs 177provide an audible click when the legs 176 deflect outward into thetransverse locking passage 157 to confirm positive engagement for theuser. The user can also visually confirm proper positioning of theadapter 170 because the alignment ridge 178 should align with theindicator arrow 123 on the socket end 156 as shown in FIG. 19.

Referring to FIGS. 18 and 19, after positioning the adapter 170 on thedrive shaft 160, the implant 200 can be partially engaged to the tip 113by a snap friction fit. The tip 113 is slightly compressed, by virtue ofthe slots 109, and passed into the proximal internal recess 250 of theimplant 200 with the blades 220 a, 220 b of the implant 200 aligned withthe slots 109, arrow 123 and stripes 127 of the main body 102. As aresult, the surgeon can determine proper blade orientation visuallyprior to and during insertion. The tip 113 stops within the recess 250when the ridges 111 seat into the transverse groove 253. At this point,the implant 200 is coupled to the insertion instrument 100 but not yet“locked.”

To lock the implant 200 to the instrument 100, the plunger 110 is movedfrom the unlocked position to the locked position. To move the plunger110 distally, the plunger knob 126 is rotated clockwise (looking fromthe proximal end). As the threads are left-handed, the plunger 110 willmove towards the distal tip 113. As the plunger 110 moves, the firstdistal axial groove portion 119 passes along the boss 139 of the plungerstop 132 until the boss 139 aligns with the radial portion 121 of thegroove 116. When the boss 139 aligns with the radial portion 121 of thegroove 116, the plunger stop 132 rotates clockwise because of the biasof the spring 141. The boss 139 passes into the radial portion 121 andfurther axial movement is prevented. The reference notch 131 of the wing120 is at the locked indicia 105 b and the insertion instrument is inthe locked position.

In the locked position, the distal pushing end 112 of the plunger 110 isapproximately flush with the distal tip 113 of the main body 102. Thus,the slots 109 of the main body 102 can no longer flex to allow theridges 111 out of the transverse groove 253 best seen in FIG. 22.Consequently, the implant 200 is tightly coupled and locked to the tip113 so that inadvertent removal does not occur. The insertion instrument100 is now ready to have the socket end 156 of the spike cap drive 140engaged to the hex nut 235 of the implant 200.

To engage the spike cap drive 140 to the hex nut 235 of the implant 200,the handle portion 148 is held to prevent rotation while the drive shaft160 is rotated to bring the pins 165 out of the radial portion 164 ofthe slots 161. The spring 163 will bias the drive shaft 160 outward socare should be taken to slowly extend the drive shaft 160 to have thehex socket 172 properly engage the hex nut 235 of the implant 200 (bestseen in FIG. 22). In order to have the hex socket 172 properly engagethe hex nut 235, a slight manual rotation or jiggle of the drive shaft160 may be required. The implant 200 is now locked to the insertioninstrument 100 to be ready for spinal implantation. The force providedby the spring 163 is optimized to insure proper, reliable engagementbetween the adapter 170 and hex nut 235 while providing excessive forceto interfere with the operation of the insertion instrument 100 ordeployment of the implant 200.

Deploying the Implant in the Interspinous Space

FIGS. 20-24 illustrate various stages during insertion and placement ofthe implant 200 into a target interspinous process space 382. In short,FIG. 20 is a perspective view of the implant 200 locked to the insertioninstrument 100, in preparation to be installed dorsally through a curvedintroducer tube 387, which has been inserted through an incision 389formed through the skin 388 of a patient. FIG. 21 is a dorsal (rear)view of the implant 200, still held by the elongated insertioninstrument 100, within a lumen of an introducer tube 387, during lateralinsertion thereof.

FIG. 22 is a dorsal view illustrating the implant 200 being laterallyadvanced to the target interspinous process space 382, under applicationof a rotational force applied by the insertion instrument 100, by virtueof the threads 222 provided on the body 212 thereof. FIG. 27 is a dorsalview illustrating the implant 200 with the internal implant plunger 226urged distally, effecting deployment of the distal anchor elements—inthis case, blades 220 a, 220 b. The nut 235 is then tightened, whichurges the body 212 proximally, and thus also urges the blades 220 moresecurely against the adjacent bony structure, impinging the spinousprocesses 381 a, 381 b there between, as shown in FIG. 28, which is adorsal view illustrating the implant 200 with the spike cap 230 urgeddistally by the nut 235, engaging the adjacent spinous processes 381 a,381 b. FIG. 30 is a dorsal view illustrating the implant 200 fixed inplace with removal of the insertion instrument 100.

More particularly, as seen in FIG. 20, a sleeve 387 is provided tofacilitate insertion. The insertion methods can include use of a stylet,dilators, and the like to gain access and define a path for the sleeve387, as will be described in more detail below. However, dorsalinsertion can be accomplished as set forth in U.S. patent applicationSer. No. 12/011,905, filed Jan. 30, 2008 (U.S. Pub. No. 2009/0054988),which is incorporated herein by reference in its entirety.

As illustrated, in FIG. 20, dorsal insertion of the subject implants,represented by implant 200, can be effected by forming an incision 389through the skin 388 of a patient, at a level corresponding to a targetinterspinous process space 382, defined between adjacent vertebralprocesses 381 a, 381 b. With dorsal entry illustrated in FIG. 20, thepath traversed by the implant 200, and therefore also by the sleeve 387is curved to align the path and the implant 200 with the targetinterspinous process space 382. As such, the insertion instrument 100may be flexible and/or curved to match the curve of the sleeve 387.

FIG. 21, in contrast, illustrates direct lateral insertion of theimplant 200 into the target interspinous process space 382. In thisarrangement, an incision is formed in the skin 388 of a patient, andultimately a sleeve 387 is advanced through the tissue to the targetinterspinous process space 382, through which the implant 200 isadvanced, connected to the insertion instrument 100. As shown in FIGS.21 and 22, of which FIG. 22 is illustrated for clarity without thesleeve 387, the implant 200 is axially rotated by way of the insertioninstrument 100, thus threading the implant 200 into the targetinterspinous process space 382, distracting the adjacent spinousprocesses 381 a, 381 b, and advancing the implant 200, generallycentered with respect to the spinous processes 381 a, 381 b.

To rotate the implant 200, the proximal handle portion 103 of the mainbody 102 is rotated in a tightening or clockwise direction toself-thread the implant 200 through the interspinous space 382 as shownin FIG. 22. During the rotation of the implant 200, the implant 200distracts the interspinous space. Relative rotation and axialtranslation between the implant 200 and the insertion instrument 100 isinhibited because the implant 200 is locked onto the tip 113 by thedistal pushing end 112 of the plunger 110. Distraction can also beperformed in advance by a separate instrument, with insertion of theimplant 200 following, and maintaining such distraction.

When anchoring blades 220 a, 220 b have passed through the interspinousspace 382 as shown in FIG. 27, the anchoring blades 220 a, 220 b can bedeployed. Referring now to FIGS. 23 and 24, to deploy the anchoringblades 220 a, 220 b, the plunger stop 132 is rotated so that the boss139 moves out of the radial groove portion 121 of the plunger 110. Assuch, the plunger 110 becomes free to move with the axial portion 125sliding along the boss 139 of the plunger stop 132 as shown best in FIG.24. To accomplish the proximal movement of the plunger 110, the plungerstop 132 is held and the plunger knob 126 is turned clockwise or in atightening motion. Because the threading is left-handed, the plunger 110will move away from the plunger knob 126. The reference notch 131 willslide toward the “deployed” position indicia 105 c as the secondproximal axial groove portion 125 rides along the boss 139.

As the plunger 110 extends distally, the distal pushing end 112 seats inthe recess 221 of the implant plunger 226. As the plunger 110 continuesto move distally, the pushing end 112 applies pressure and moves theimplant plunger 226 distally to deploy the blades 220 a, 220 b as shownin FIG. 27. Once fully deployed, the reference notch 131 will beadjacent the “deployed” indicia 105 c and turning of the plunger knob126 can stop. The physician can also verify proper deployment of theblades 220 a, 220 b by fluoroscopy. Once the blades 220 a, 220 b aredeployed, the implant 200 can be set in final position.

Referring now to FIG. 28, the hex nut 235 of the implant 200 is shownbeing driven by the spike cap drive 140 to engage the spikes 224, 234 tothe spinous processes 381 a, 381 b. The spike cap drive 140 rotates thehex nut 235 to move the spike cap 230 distally. Because the spike cap230 is keyed to the implant 200 to prevent rotation, as the hex nut 235turns, the spike cap 230 slides distally.

To rotationally drive the hex nut 235, the spike cap drive 140 isrotated clockwise relative to the main body 102 by the handle portion148. Turning the handle portion 148 turns the adapter 170 and therebythe hex nut 235. Once the spike cap 230 engages the spinous processes381 a, 381 b, the blades 220 a, 220 b are drawn proximally intoengagement with the bone 381 a, 381 b. A flat portion of the implant 200is not threaded so that the implant 200 slides proximally. While thespike cap drive 140 is used to tighten the hex nut 235, the surgeon canfeel the spike cap 230 become fully seated or full seating is seen in anaccompanying fluoroscopy display. Preferably, one or more osteogenesispromoting substances can be packed in and/or around the implant 200 topromote bone ingrowth and/or spinal fusion, if desired.

A separate tap can be used in the target interspinous process space 382before the insertion of the implant 200, or as mentioned above, theimplant 200 can be provided with features that provide self-tappingcapability. Methods of lateral insertion of the spinal implant 200 intoa target interspinous process space 382 can include, following formingthe incision, inserting a stylet (not illustrated) through the incision399, laterally to the target interspinous process space 382, preferablyusing an internal imaging technique, such as fluoroscopy.

Referring now to FIGS. 29 and 30, once the implant 200 is properlydeployed, the insertion instrument 100 is disengaged from the implant200. To disengage the insertion instrument 100, the drive shaft 160 ofthe spike cap drive 140 is retracted into the intermediate portion 154with the pins 165 captured in the radial portion 164 of the slot 161following the same procedure as described above so that the adapter 170disengages from the hex nut 235. The plunger stop 132 is rotated andheld by the user's thumb so that the groove 116 will ride from theproximal axial portion 125 to the distal axial portion 119 withoutpassing into the radial portion 121. To withdraw the plunger 110, theplunger knob 126 is loosened or rotated in the counter-clockwisedirection relative to the handle portion 104 of the main body 102 untilthe reference notch 131 fully indicates the “unlocked” position next tothe unlocked indicia 105 a. As the plunger 110 withdraws from the tip113, the slots 109 are again allowed to flex so that the tip 113 popsout of the proximal internal recess 250 of the implant 200. With theadapter 170 disengaged and the plunger 110 retracted to the unlockedposition, the coupling force of the tip 113 to the implant 200 can beovercome to fully detach the insertion instrument 100. Once removed, theinsertion instrument 100 can be removed from the patient fordisassembly, cleaning and re-use.

Referring now to FIGS. 29 and 30, once the implant 200 is properlydeployed, the insertion instrument 100 is disengaged from the implant200. To disengage the insertion instrument 100, the plunger knob 126 isloosened or rotated in the counter-clockwise direction relative to thehandle portion 104 of the main body 109 to withdraw the plunger 110until the reference notch 131 fully indicates the “locked” position nextto the unlocked indicia 105 b. The plunger stop 132 clicks over,bringing the boss 139 into the radial groove portion 121, and engages toprevent further loosening of the plunger 110. The plunger stop 132 isrotated and held by the user's thumb so that the groove 116 will ridefrom the radial groove portion 121 to the distal axial portion 119. Thisretraction of the plunger 110 may also be accomplished without the boss139 passing into the radial groove portion 121. As the plunger 110withdraws from the tip 113 by further counter-clockwise rotation of theplunger knob 126, the slots 109 are again allowed to flex so that thetip 113 can pop out of the proximal internal recess 250 of the implant200. With the adapter 170 disengaged and the plunger 110 retracted tothe unlocked position, the coupling force of the tip 113 to the implant200 can be overcome to fully detach the insertion instrument 100. Onceremoved, the insertion instrument 100 can be removed from the patientfor disassembly, cleaning and re-use.

Disassembly of the Insertion Instrument

It is advantageous to disassemble the insertion instrument 100 forcleaning. Referring to FIGS. 3-10 in reverse, the locking tabs 117 thatretain the plunger 110 are flipped up to unlock the plunger 110. As longas the plunger 110 is in the unlocked position, the plunger 110 can thenbe removed from the main body 102. The plunger knob 126 can be unscrewedfrom the plunger 110. Once the plunger 110 is removed, the plunger stop132 can also be removed from the main body 102. Next, the locking tabs115 that retain the spike cap drive 140 are released so that the spikecap drive 140 can be removed from the main body 102. The adapter 170 canbe unsnapped from the spike cap drive 140. At this point, the componentsof the insertion instrument 100 are ready to be cleaned.

Below is Table 1, which is a parts list for the insertion instrument 100and implant 200 illustrated in the figures.

TABLE 1 Part Ref. No. insertion instrument 100 elongated main body 102axial wing slot 103 proximal handle portion 104 “unlocked” positionindicia 105a “locked” position indicia 105b “deployed” position indicia105c central passage 106 distal portion 108 forms axial slots 109plunger 110 outer ridges 111 distal pushing end 112 tip 113 locking end114 locking tabs 115 groove 116 second pair of opposing locking tabs 117radial holes 118 first distal axial groove portion 119 opposing radialwings 120 radial groove portion 121 proximal recess 122 indicator arrow123 axial threaded post 124 second proximal axial groove portion 125plunger knob 126 stripes 127 threaded distal end 128 proximal handleportion 130 reference notch 131 plunger stop 132 distal guide portion133 axial recess 134 angled surface 135 axial passage 136 tubularportion 137 outer opposing lands/thumb lands 138 boss 139 spike capdrive 140 biasing spring 141 annular recess 142 ends 143 axial passage144 proximal portion 146 handle portion 148 interlocking portion 150annular groove 152 intermediate portion 154 socket end 156 transversesquare locking passage 157 square opening 158 drive shaft 160complimentary slots 161 spring 163 radial portion 164 pins 165 pin holes167 adapter 170 hex socket 172 central axial passage 173 standard malesquare open proximal end 174 rigid legs 175 flexible legs 176 lockingtab 177 outer axial alignment ridges 178 implant 200 body 212expanded-diameter portion 213 apertures 214 flat portions 217 blades 220proximal internal recess 221 threads 222 hinge portions 223a, 223bspikes 224 proximal head 225 plunger 226 catch 227 head portion 228recess 229 spike cap 230 lock washer 233 hex nut 235 guidecorrespondingly shaped portions 237 inner cam surfaces 240 detent 249bore 250 shaped socket 251 transverse grooves 253 annulargrooves/recesses 254 pin 259 spring element 281 spinous processes 381a,381b interspinous process space 382 introducer tube 387 skin 388incision 389 insertion device 392

Many of the primary structural components of the implant devicesdescribed herein are preferably formed from biological and/orbiocompatible materials, including metal, ceramic, polymeric and/orcomposite materials that can be selected to have a modulus of elasticitythat is substantially similar to that of bone, for example,polyetheretherketone thermoplastic (PEEK), machined bone, a titaniumalloy or stainless steel, for example. The insertion instrument canadditional take advantage of polytetrafluoroethylene (PTFE) plastic withlow coefficients of friction, abrasion resistance, a wide range ofoperating temperatures, and chemical inertness to form bearing surfaceson the rotating components to prevent metal wear and galling. PTFE isparticularly useful for the portions of adjacent components that rotatewith respect to each other.

While the apparatuses and methods of subject invention have been shownand described with reference to preferred embodiments, it is to beunderstood that any feature described in connection with one embodimentcan be advantageously applied to other embodiments of the invention,even if not explicitly described in connection therewith, if suchfeature(s) are not mutually exclusive with other features of suchembodiment. Nevertheless, those skilled in the art will readilyappreciate that further changes or modifications may be made to devicesand methods of the present invention without departing from the spiritand scope thereof. It is also to be appreciated that the followingclaims can be rearranged, combined, combined with other featuresdisclosed herein, presented in multiple dependent form and the like.

What is claimed is:
 1. An insertion device for a spinal implant, wherein the spinal implant includes: a) an elongated body to function as a spacer placed in a target interspinous process space between two adjacent spinous processes, wherein the body defines an interior and a proximal internal recess for access to the interior, the proximal internal recess forming a transverse groove; b) a distal anchor that is at least partially threaded and has opposing radially deployable blades mounted for rotation about a pin transversely mounted in the interior; c) a proximal anchor including a spike cap mounted to slide along the body and a drive nut mounted for longitudinal movement along the body between a first position spaced apart from the distal anchor and a second position relatively closer to the distal anchor to thereby compress the two adjacent spinous processes between the spike cap and the distal anchor; and d) an actuation plunger slidably inside the interior for moving the blades from a stowed position to an implant deployed position, the insertion device comprising: an elongated main body having a distal locking portion for coupling to the implant and a proximal handle portion, the main body defining a central passage and the distal locking portion having outer ridges and at least one slot to allow at least one of the outer ridges to flex radially inward; a plunger slideably coupled in the central passage for movement between an unlocked position for mounting the implant on the distal locking portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the actuation plunger to move the blades from the stowed position to the deployed position; and a spike cap drive rotatably mounted on the main body having a socket end for engaging the drive nut to, in turn, move the spike cap.
 2. An insertion instrument as recited in claim 1, further comprising a plunger stop coupled to the main body, the plunger stop having a central passage substantially aligned with the central passage of the main body, wherein: the plunger stop has a boss protruding into the central passage; and the plunger forms a three-part groove that captures the boss as the plunger slides and rotates within the central passage, the three-part groove having a first axial part that defines the unlocked position, an intermediate radial part that defines the locked position, and a second axial part that defines the insertion instrument deployed position.
 3. An insertion instrument as recited in claim 1, wherein: in the unlocked position, when the implant is mounted on the insertion instrument, the outer ridges are engaged in the transverse groove; in the locked position, the outer ridges are engaged in the transverse groove and the plunger extends through the central passage to be concentric with the outer ridges; and in the insertion instrument deployed position, the plunger extends out of the central passage to move the actuation plunger of the implant.
 4. An insertion instrument as recited in claim 1, further comprising an adapter matched to the implant for coupling the socket end to the drive nut of the implant.
 5. An insertion instrument as recited in claim 1, wherein the spike cap is keyed to the implant body to prevent rotation when driven and the implant has flat portions that allow efficient compression of the implant when engaged in the spinous processes.
 6. An insertion instrument as recited in claim 1, further comprising polytetrafluoroethylene (PTFE) on at least one of the spike cap drive or main body to reduce wear and provide smooth operation as the spike cap drive is rotated.
 7. An instrument for inserting an implant having a threaded body, selectively deployable distal blades, and a selectively deployable proximal anchor, the instrument comprising: an elongated main body having a proximal handle portion that defines a central passage and a distal portion that selectively couples to the implant; a plunger slidably engaged in the central passage to fix the implant to the elongated main body and deploy the distal blades; and a spike cap drive concentrically located about the plunger to deploy the proximal anchor.
 8. An instrument as recited in claim 7, wherein the implant defines an interior with a transverse groove, the distal portion snaps into the transverse groove, and the plunger slides down central passage to prevent the distal portion from unsnapping from the transverse groove.
 9. An instrument as recited in claim 7, wherein the plunger moves between an unlocked position for mounting the implant on the distal portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the blade.
 10. An insertion instrument for inserting an implant having a body that defines a mounting recess, the insertion instrument comprising: an elongated main body having a proximal handle portion and a slotted distal portion that selectively couples to the mounting recess of the implant; and a plunger slidably engaged in a central passage of the elongated main body for fixing the implant to the elongated main body by selectively filling the central passage within the slotted distal portion.
 11. An insertion instrument as recited in claim 10, wherein the implant defines an interior connected to the mounting recess, the implant further includes selectively deployable distal blades, and the plunger deploys the distal blades by extending out of the central passage into the interior.
 12. An insertion instrument as recited in claim 10, wherein the implant further includes a selectively deployable proximal anchor and the insertion instrument further comprises a spike cap drive concentrically located about the plunger and elongated main body to deploy the proximal anchor.
 13. An insertion instrument as recited in claim 10, wherein: the spike cap drive defines an axial passage; the spike cap drive has a proximal handle portion slidably coupled with a smaller radius interlocking portion that terminates in a socket end; the smaller radius interlocking portion can be locked in a retracted position; and the spike cap drive has a spring mounted within the proximal handle portion for biasing the smaller radius interlocking portion distally.
 14. An insertion instrument as recited in claim 10, wherein the mounting recess has a transverse groove, the distal portion has ridges that snap into the transverse groove.
 15. An insertion instrument as recited in claim 10, wherein the plunger moves between an unlocked position for mounting the implant on the distal portion, a locked position for locking the implant on the distal locking portion, and an insertion instrument deployed position for deploying the blade. 